It is generally known to detachably mount an oil pan on the bottom of the crankcase of an internal combustion engine in order to collect the lubricating oil that flows down from the various lubricated locations within the engine. It is necessary to provide a fluid-tight seal between the oil pan and the bottom of the crankcase, which is typically achieved using a rubber-elastic seal ring or gasket. This seal ring or gasket may be arranged to be received in grooves running along the rim of the oil pan, and to be pressed and seated against a sealing surface provided along a bottom rim of the crankcase. Such a seal arrangement is known, for example as described in German Patent 3,815,511 (Pickard et al.).
Furthermore, engine and oil pan configurations are known in which a top rim of the oil pan is sealed against the bottom of the crankcase, while an open end face of the oil pan is closed or sealed by the housing of an equipment mount or other engine component, which is sealed against the end face rim of the oil pan. Since the top sealing rim of the oil pan is substantially horizontal, while the end face sealing rim of the oil pan is substantially vertical, the two rims on the respective wall of the oil pan form a corner that must be sealed at the location where the top sealing rim and end face sealing rim meet each other. To provide the necessary seal along the top rim facing the crankcase and along the end face rim, which extends substantially orthogonally to the top rim, a seal member is arranged in grooves, to run along the entire perimeter path of the oil pan rim.
However, it is difficult to provide an effective seal directly at the corner in the known arrangement. An edge extending perpendicularly to the extension direction of the seal member is formed along the intersection of the two rim surfaces that meet each other substantially at a right angle as described above. The seal member, which lies in one plane as it runs over or around this intersection edge, cannot achieve a reliable seal, because it cannot be uniformly and tightly pressed by and against the corresponding sealing surfaces of the components in this area due to the bending or turning of the seal. Namely, if the seal member turns around the corner in the groove in one plane, then there is no counter-surface for the seal member to be pressed against immediately at the corner, and the seal in this corner region will be subjected to pressing forces along its lengthwise extension direction (i.e. the direction of the groove). Since the seal is not properly pressed against a counter-surface, and instead is pressed or pushed along the groove, a proper seal compression cannot be achieved and the resulting seal will tend to leak directly at the corner.